Reset to defaults
Need help?How to Convert SWF to MP4 Online
- Upload Your SWF File: Drag and drop or click "Add Files" to select SWF files that contain video — Flash video players, exported Flash videos, or e-learning SWFs with an embedded video track. Batch is supported — add several files and each converts in parallel.
- Pick Quality Preset or Bitrate Mode: Default is the "Very High (Recommended)" Quality Preset, which targets visually-lossless H.264 output at the SWF's native frame rate. Switch to Specific file size to cap output at an exact MB value, Constant Bitrate for predictable streaming sizes, Variable Bitrate for smaller files at the same quality, or Constant Quality to fine-tune with a CRF slider (18 = visually lossless, 23 = default, 28 = noticeably smaller).
- Resize or Trim if Needed (Optional): Under Video resolution, keep original, pick a Preset Resolution (1080p / 720p / 480p / 360p down through 240p — most SWFs were authored at 550×400, 640×480, or 800×600 stage sizes so 720p is plenty), scale by Resolution Percentage, or enter custom Width × Height. Under Trim, choose Time Range and enter start + duration to drop intros or ads.
- Convert and Download: Click Convert. The video inside your SWF is converted to H.264 MP4 on our servers — no Flash Player needed, no sign-up, no watermark. Download individually or as a ZIP.
Why Convert SWF to MP4?
SWF (originally "ShockWave Flash," rebranded to "Small Web Format") was the dominant interactive web animation format from FutureSplash Animator's 1996 release through Adobe's official Flash Player end-of-life on December 31, 2020. On January 12, 2021, Adobe pushed an update that blocks all Flash content from running in the official Flash Player. Every major browser — Chrome, Firefox, Edge, Safari — removed Flash support around the same time. The only ways to view SWF content today are emulators like Ruffle or converting to a modern format. MP4 (ISO/IEC 14496-14, standardized in 2003) plays on every device, every browser, every editor, with zero plugin requirements. Common reasons to convert:
- Rescue the video inside old Flash files — many 2000s-era sites wrapped their clips in a SWF player. Converting that embedded video to H.264 MP4 makes it playable on phones, smart TVs, and modern browsers indefinitely. Vector cartoons (most Newgrounds or Albino Blacksheep animations) have no video inside to convert — play those in the free Ruffle player.
- Reupload to YouTube, TikTok, or Instagram — these platforms only accept modern containers (MP4, MOV, WebM). Converting the video inside your old Flash file lets you re-share it to an audience that can't run SWF natively.
- Embed in modern slide decks — PowerPoint dropped Flash embedding in Office 2019 / 365; Google Slides and Keynote never supported SWF. MP4 embeds cleanly in all three.
- School and corporate e-learning migration — countless Articulate, Captivate, and Lectora courses were published to SWF before HTML5 export became standard around 2015. Converting the SWF assets to MP4 preserves the content for LMS platforms that have disabled Flash playback.
- Replace dead Flash embeds on legacy websites — if you still maintain a 2008-era site with
<embed src="intro.swf">, swap in<video src="intro.mp4">so visitors on iPhones, modern Chrome, and corporate-locked browsers actually see the content.
SWF vs MP4 — Format Comparison
| Property | SWF | MP4 |
|---|---|---|
| Standard | Adobe Flash (spec opened May 2008 under Open Screen Project) | ISO/IEC 14496-14:2003 |
| Origin | FutureSplash Animator 1996 → Macromedia Flash → Adobe (2005) | MPEG-4 working group, derived from QuickTime |
| Status | EOL Dec 31, 2020; blocked by Flash Player since Jan 12, 2021 | Active, universally supported |
| Content type | Vector animation, ActionScript bytecode, raster, audio, video | Container for H.264/H.265/AV1 video + AAC/MP3 audio |
| Interactivity | Yes — ActionScript 1/2 (AVM1) or 3 (AVM2) | None (passive video) |
| Native playback today | None in any mainstream browser; requires Ruffle emulator or Adobe Flash Player projector (offline only) | Every browser, every modern OS, every smart TV, every editor |
| Typical file size | Small for vector content (KB-range animations) | Larger (raster video) but predictable per minute of playback |
| Best for | Source archive only — keep alongside MP4 export | Sharing, editing, embedding, long-term playback |
Quality and Bitrate Mode Quick Guide
| Mode | What it does | Pick when |
|---|---|---|
| Quality Preset | One-click Highest → Lowest preset (default "Very High") | You want a sensible default with no tweaking |
| Specific file size | Auto-tunes bitrate to hit an exact MB target | You're hitting a Discord, email, or upload cap |
| Constant Bitrate (CBR) | Fixed bits per second across the entire video | Predictable sizing, broadcast workflows |
| Variable Bitrate (VBR) | Spends more bits on complex scenes, fewer on simple | Best quality-per-MB; default for most uploads |
| Constant Quality (CRF) | CRF 16-51 — 18 = lossless, 23 = default, 28 = small | You want consistent perceived quality across clips |
| Constraint Quality (capped VBR) | VBR with a ceiling bitrate | Streaming where bandwidth has a hard ceiling |
For most SWF video, CRF 20-22 produces an MP4 that's visually indistinguishable from the source at a fraction of the file size of the "Highest" preset. For richer audio tracks (Flash music videos), bump audio bitrate in Advanced Options. Want a looping clip as a shareable image? Try SWF to GIF. Editing on a Mac? Pull the result into Final Cut by going SWF to MOV. Need just the audio? SWF to MP3 extracts the soundtrack only.
Frequently Asked Questions
Why can't I just play my SWF file anymore?
Adobe ended Flash Player support on December 31, 2020, and on January 12, 2021, pushed an update that blocks all SWF content from running in the official player. Chrome, Firefox, Edge, and Safari all removed Flash plugin support around the same time. SWF files on your computer are still intact — they just have nothing to play them in. Options today are: convert to MP4 (best for sharing and long-term viewing), use the open-source Ruffle emulator (best for interactive games and animations you want to keep clickable), or run the offline Flash Player projector if you still have it. For a SWF that contains video, converting to MP4 is the simplest way to watch it on phones and smart TVs; vector animations and games play in Ruffle instead.
Will my SWF's interactivity (clicks, ActionScript) be preserved?
No. MP4 is a passive video container — it holds frames and audio, not code. If your SWF has clickable menus, branching paths, mini-games, or any ActionScript-driven behavior, none of it is carried over — only the video stream inside the SWF converts, and a SWF that is only a game or a vector animation can't be converted at all. For interactive content preservation, use Ruffle — it covers roughly 90% of AS3 language features and ~77% of the AS3 API, with over 99% AS1/AS2 coverage in a modern browser. Use SWF to MP4 for the video inside a SWF; use Ruffle for vector animations and games.
My SWF converts to a black or blank MP4 — why?
Usually because the picture was never a video. Vector animations and games are drawn by Flash at playback time, so there is no video stream to convert — we tell you right after upload when a SWF is one of these, and nothing is converted. If your SWF does carry video but loads it from a server that no longer exists, there is nothing in the file to convert either; only video embedded in the SWF can be converted. To watch a vector animation or game, open it in Ruffle, or screen-record a Ruffle playthrough.
What resolution should I pick for an old Flash animation?
Most SWFs from the 2000s were authored at stage sizes of 550×400, 640×480, 720×540, or 800×600 — sub-720p by modern standards. Picking 1080p won't add detail — the video inside the SWF was encoded at a fixed size. Match or modestly exceed the stage size: 720p covers nearly every SWF from that era without wasting file size. For HD-authored later-era SWFs (some 2012-2020 Articulate / Adobe Animate exports), pick 1080p. Use Width × Height to lock to the SWF's original aspect ratio if you don't know what it was authored at.
Will the audio track be preserved?
Yes. Embedded audio in SWF (MP3 streams or ADPCM samples for sound effects) is decoded and re-encoded to AAC inside the MP4. Flash music videos and voiceovers keep their audio. If your SWF loads audio externally (loadSound() calls to a server URL) and that server is dead, the audio won't be in the output — only embedded audio survives. Streamed audio in the SWF timeline is preserved with frame-accurate sync.
What's the file size limit?
XConvert handles SWF files of any size — most legacy SWFs are well under 50 MB, often just a few hundred KB for short animations. The output size depends mostly on the quality preset and resolution you pick. There's no per-file cap and no quantity limit on batch jobs.
Is my SWF safe to upload — are old Flash files a security risk?
Adobe's Flash Player vulnerabilities (CVE backlog through 2020) required the Flash Player runtime to exploit them. Converting a SWF to MP4 server-side via XConvert never executes the ActionScript in a Flash runtime — only the video stream inside the SWF is read and re-encoded. You're not exposing your browser or device to any Flash exploits during conversion. The resulting MP4 is plain video with no executable component.
Can I convert multiple SWF files at once?
Yes. Upload as many SWF files as you want and apply the same settings to all of them, or set per-file options. Each file converts in parallel on our servers and downloads individually or as a single ZIP. Handy for migrating an e-learning course's SWF video assets in one pass.
Can I cut a long SWF down before converting?
Yes — under Trim, pick Time Range and enter a start time and duration (seconds like 12.5 or HH:MM:SS.sss like 00:01:30.500). Useful for stripping pre-loader animations, sponsor logos, or "click to play" intros that don't need to be in your archived MP4. For finer cutting after conversion, see Trim SWF for source-side or Compress MP4 to shrink the result further.